The overall goal of this K23 proposal is to train Sharon J. Herring, M.D., M.P.H. for a career as an independent investigator in obesity research, with specific emphasis on obesity prevention and treatment for women. Obesity is a rapidly growing area of investigation, but relatively few researchers have focused on prevention and treatment among low-income, Black women at vulnerable points in the life course. In the proposed award, Dr. Herring plans to address this gap in knowledge by focusing her research on weight gain prevention for Black women during the puerperal period, a critical time for young Black women to experience - or avoid - excess weight gain and new or persistent obesity. As Black women have among the highest rates of obesity in the U.S., interventions that reduce postpartum weight retention have the potential to minimize weight gain and lower Black women's risk of cardio-metabolic morbidity and mortality. Dr. Herring proposes two complementary studies to minimize weight retention among overweight or moderately obese low-income, Black mothers after childbirth. Study 1 aims to understand the influence of social contextual factors on Black mothers' peripartum weight-related behaviors through a series of longitudinal, in-depth interviews during pregnancy and over the first postpartum year. This information will be used to design and modify the messages and communication strategies for a pilot randomized controlled trial among Black mothers (Study 2). Study 2 will use a randomized controlled trial design to assess the efficacy of a web-based, pregnancy and postpartum behavioral intervention on changes in 1-year postpartum body weight and cardio-metabolic biomarkers compared to a usual care control condition. To successfully complete this research plan, Dr. Herring will receive additional training through formal coursework and structured mentorship in: 1) qualitative methods; 2) conduct of clinical trials for obesity prevention and treatment; and 3) cardio- metabolic processes accompanying peripartum weight change. The environment at Temple University is characterized by a supportive, accomplished multi-disciplinary mentorship team; access to a large number of low-income, Black mothers; formal coursework in qualitative and quantitative research methodology; and hands-on, laboratory-based skills training in fuel metabolism. Findings from the proposed studies will provide novel, clinically relevant information and enable Dr. Herring to develop her career as an independent investigator in obesity research.